#include<iostream>
#include<vector>

using namespace std;

bool check[301][301];
int m, n;
int dx[4] = { 0,0,1,-1 };
int dy[4] = { 1,-1,0,0 };

void dfs(vector<vector<char>>& grid, int i, int j)
{
    for (int k = 0; k < 4; k++)
    {
        int x = i + dx[k], y = j + dy[k];
        if (x >= 0 && x < m && y >= 0 && y < n && !check[x][y] && grid[x][y] == 1)
        {
            check[x][y] = true;
            dfs(grid, x, y);
        }
    }
}
int numIslands(vector<vector<char>>& grid) {
    int ret = 0;
    m = grid.size(), n = grid[0].size();
    for (int i = 0; i < m; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (!check[i][j] && grid[i][j] == 1)
            {
                check[i][j] = true;
                dfs(grid, i, j);
                ret++;
            }
        }
    }

    return ret;
}


int main()
{


    return 0;
}
